Wire stripping and wrapping gun

ABSTRACT

A wire stripping and wrapping gun includes a wrapper pin, a lever knife and an actuating device. The actuating device moves the wrapper pin axially and causes the knife to strip the insulation from the wire. The cutting edge of the lever knife is bifurcated to include a channel wide enough to receive the bare wire. A circular aperture is provided to be contiguous with the channel to relieve the pressure tending to be built up in the insulation being stripped and causing the insulation to crimp or jam the knife. The crimping and jamming may be further alleviated by making the inner surface of the knife facing the insulation concavely curvatured.

Inventor Bruno Staiger Rosenfeld, Germany Appl. No. 44,827 Filed June 9,I970 Patented Dec. 21, 1971 Assignee International Standard ElectricCorporation New York, N.Y. Priority June 16, 1969 Germany WIRE STRIPPINGAND WRAPPING GUN 4 Claims, 6 Drawing Figs.

[56] References Cited UNITED STATES PATENTS 2,696,656 12/1954 Madden7/14! Primary Examiner-Theron E Condon Assistant Examiner- Roscoe V.Parker, J r.

Attorneys-C. Cornell Remsen, Jr., Walter J. Baum, Paul W.

Hemminger, Charles L. Johnson, .lr., Philip M. Bolton, Isidore Togut,Edward Goldberg and Menotti J. Lombardi, Jr.

ABSTRACT: A wire stripping and wrapping gun includes a wrapper pin, alever knife and an actuating device. The actuating device moves thewrapper pin axially and causes the knife to strip the insulation fromthe wire. The cutting edge of the lever knife is bifurcated to include achannel wide enough to receive the bare wire. A circular aperture isprovided to be contiguous with the channel to relieve the pressuretending to be built up in the insulation being stripped and causing theinsulation to crimp or jam the knife. The crimping and jamming may befurther alleviated by making the inner surface of the .knife facing theinsulation concavely clurvatured.

3 2 l l O BEEN m SHEU 1 BF 2 INVENTOR ATTORNEY BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relates to awire stripping and wrapping gun or tool for cutting and stripping wires,as well as for making wire-wrap joints, and, more particularly, to animproved cutting edge in the knife provided in such a gun or tool.

2. Description of the Prior Art Prior art, such as the copending U.S.Pat. application Ser. No. 851,847, filed on Aug. 21, 1969, and assignedto the same assignee as the instant application, shows a wire strippingand wrapping gun for cutting and stripping of the insulation from thewire, as well as, for producing wire-wrap joints. The gun includes awrapper pin slidably mounted within a centrally and axially aperturedwrapper sleeve for imparting the wrapping and stripping movement, and alever knife with the cutting edge thereof pivotally mounted on thewrapper sleeve. As the wrapper pin is axially moved the cutting edge islowered upon the wire against an upstanding portion of the wrapper pinpositioned therebelow, and cuts the insulation on both sides and, in thecourse of a further axial movement, the insulation is stripped from thewire.

According to the wire stripping and wrapping gun shown in theaforementioned copending application, the lever knife has a simplestraight cutting edge. It has been found that the straight cutting edgecuts the edges of the insulation only partially and does not readilyremove the stripped insulation.

SUMMARY OF'THE INVENTION It is an object of the present invention toprovide an improved wrapping and stripping tool in general and, inparticular, to provide an improved cutting edge in the lever knife toovercome the aforementioned shortcomings.

This and other objects of the present invention are achieved byproviding a channel in the cutting edge of the knife wide enough toreceive the bare metal wire and a curved aperture contiguous therewith.The bifurcated cutting edge formed by the channel is designed to cutthrough both sides of the insulation of the wire completely, and thecircular aperture prevents the insulation from being crimped or clampedalong the cutting edge and piling up as it is being stripped.

It is a further feature of the present invention that the inner surfaceof the bifurcated cutting edge facing the insulation being stripped isconcavely curvatured to further assure avoidance of the crimping andclamping and maintain mechanical stability of the cutting edge.

It is another feature of the present invention that the width of thechannel is made to correspond to the diameter of the bare wire after theinsulation has been stripped.

The novel configuration of cutting edge of the present invention assuresclean cutting of the insulation without causing any damage to the barewire, and prevents the portion of the insulation from piling up andjamming the lever knife to hinder the subsequent stripping operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a partially sectionedview of a portion of the wrapping and stripping gun including a wrappersleeve and pin, a lever knife, and a portion ofwire which is stripped,

FIG. 2 shows a side view of a portion of the wrapper pin and the leverknife,

FIG. 3 shows the arrangement according to FIG. 2 with the wireinsulation partially stripped,

FIG. 4 shows a front view of the lever knife along section AA in FIG. 3,

FIG. 5 shows a sectional view of the cutting edge along section B--Bshown in FIG. 4, and

FIG. 6 shows a perspective view of the end of the lever knife shown inFIG. 4, with a portion thereof broken away to show the surfaceconfiguration of the cuttin ed e.

DETAILE DESGRIPTION OF I'HE INVENTION preferably pneumatic actuatingdrive means indicated by an arrow, moves the wrapper pin ll forward. Inthis manner, the insulation 6 of a wire 7 is cut and stripped away fromthe bare metal wire conductor 8.

FIG. 2 shows in detail how the lever knife 3, shown in a sectionalrepresentation, is lowered upon the wrapper pin 1. In this position theinsulation of the wire is cut by the lever knife 3. In the course of thefurther operation of the wire stripping and wrapping gun, the wrapperpin 1. moves forward and the cutting edge of the lever knife 3 stripsthe insulation ofi the wire.

FIG. 3 shows the relative positions of the lever knife 3 and wrapper pin1 after the lever knife has cut and stripped the insulation 6 from thebare metal conductor portion 8 of an insulated wire 7 inserted betweenthe wrapper pin 1 and wrapper sleeve 2, in the course of the forwardmovement of the wrapper pin 1 in the direction along the axis shown bythe arrow. The portion of the insulation which should remain on the wire8, is retained by an upturned portion 10 of the wrapper pin 1.

FIGS. 4, 5 and 6 show the novel geometry of the end 4 of the lever knifeand the cutting edge. As shown in FIG. 6, the end 4 includes a channel12 and a preferably circular aperture 13 contiguous therewith. The twoforks l5 and 16 have a concavely curvatured surface at the inner sidefacing the insulation being cut and stripped. It is preferred that thewidth of the channel be substantially equal to the diameter of the barewire so that two portions 18 and 19 of the cutting edge at the tip endsof the two forks 15 and 16 cut the two sides of the insulation sharplyand cleanly from the wire. Preferably, the diameter of the circularaperture is larger than the width of the channel. The circular apertureand the concavely apertured forks 15 and 16 relieve the pressure fromthe tip end of the insulation being cut, as the insulation is beingstripped. This prevents the crimping and clamping which would otherwisebuild up in the insulation being stripped and cause the strippedinsulation to jam against the two portions 18 and 19.

I claim:

1. A tool for cutting and stripping insulation from a wire conductorcomprising: drive means for driving the wire in a longitudinal directionwith respect to a central axis of said tool, an apertured sleevedisposed around said central axis, a pin disposed in said sleeve andcoupled to said drive means to provide axial movement of said wirewithin said sleeve, and a lever knife pivotally mounted on said sleeve,and having a bifurcated cutting edge including a channel for receivingsaid wire and a curved aperture contiguous with said channel, saidbifurcated cutting edge being disposed transversely to said wire, saidpin having means for pivotally moving said knife and causing saidcutting edge to extend through said apertured sleeve and out saidinsulation upon axial displacement of said pin, said axial movement ofsaid pin thereafter stripping the insulation from the wire.

2. The tool according to claim 1, wherein said curved aperture iscircular and has a diameter larger than the width of said channel.

3. The tool according to claim 2, wherein the inner side of said cuttingedge facing the stripped insulation is concavely curvatured.

4. The tool according to claim 3, wherein the width of said channelcorresponds substantially to the diameter of said wire conductor withthe insulation removed.

1. A tool for cutting and stripping insulation from a wire conductorcomprising: drive means for driving the wire in a longitudinal directionwith respect to a central axis of said tool, an apertured sleevedisposed around said central axis, a pin disposed in said sleeve andcoupled to said drive means to provide axial movement of said wirewithin said sleeve, and a lever knife pivotally mounted on said sleeve,and having a bifurcated cutting edge including a channel for receivingsaid wire and a curved aperture contiguous with said channel, saidbifurcated cutting edge being disposed transversely to said wire, saidpin having means for pivotally moving said knife and causing saidcutting edge to extend through said apertured sleeve and cut saidinsulation upon axial displacement of said pin, said axial movement ofsaid pin thereafter stripping the insulation from the wire.
 2. The toolaccording to claim 1, wherein said curved aperture is circular and has adiameter larger than the width of said channel.
 3. The tool according toclaim 2, wherein the inner side of said cutting edge facing the strippedinsulation is concavely curvatured.
 4. The tool according to claim 3,wherein the width of said channel corresponds substantially to thediameter of said wire conductor with the insulation removed.